1#ifdef LIBC_SCCS 2 .asciz "@(#)udiv.s 7.3 (Berkeley) 12/03/87" 3#endif /*LIBC_SCCS*/ 4 5/* 6 * udiv - unsigned division for vax-11 7 * 8 * arguments: dividend, divisor. 9 * result: quotient. 10 * uses r0-r2 11 * 12 * If 1 < divisor <= 2147483647, zero-extend the dividend 13 * to 64 bits and let ediv do the work. If the divisor is 1, 14 * ediv will overflow if bit 31 of the dividend is on, so 15 * just return the dividend unchanged. If the divisor is 0, 16 * do the ediv also, so it will generate the proper exception. 17 * All other values of the divisor have bit 31 on: in this case 18 * the quotient must be 0 if divisor > dividend, and 1 otherwise, 19 * provided that the comparison is made as unsigned. 20 */ 21 22 .text 23 .align 2 24 .globl udiv 25udiv: .word 0x0000 26#ifdef GPROF 27 jsb mcount 28#endif /*GPROF*/ 29 movl 4(ap),r0 /* dividend */ 30 movl 8(ap),r2 /* divisor */ 31 jeql 1f /* if divisor=0, force exception */ 32 cmpl r2,$1 /* if divisor <= 1 (signed), */ 33 jleq 2f /* no division is necessary */ 341: 35 clrl r1 /* zero-extend the dividend */ 36 ediv r2,r0,r0,r2 /* divide. q->r0, r->r2 (discarded) */ 37 ret 382: 39 jeql 1f /* if divisor=1, return dividend */ 40 cmpl r0,r2 /* unsigned comparison between */ 41 jgequ 2f /* dividend and divisor */ 42 clrl r0 /* dividend < divisor, return 0 */ 43 ret 442: 45 movl $1,r0 /* dividend >= divisor, return 1 */ 461: 47 ret 48 49/* 50 * audiv - unsigned division for vax-11 51 * 52 * arguments: *dividend, divisor. 53 * result: quotient in r0 and *dividend. 54 * uses r0-r2 55 */ 56 57 .align 2 58 .globl audiv 59audiv: .word 0x0000 60#ifdef GPROF 61 jsb mcount 62#endif /*GPROF*/ 63 movl *4(ap),r0 /* dividend */ 64 movl 8(ap),r2 /* divisor */ 65 jeql 1f /* if divisor=0, force exception */ 66 cmpl r2,$1 /* if divisor <= 1 (signed), */ 67 jleq 2f /* no division is necessary */ 681: 69 clrl r1 /* zero-extend the dividend */ 70 ediv r2,r0,r0,r2 /* divide. q->r0, r->r2 (discarded) */ 71 movl r0,*4(ap) /* save result */ 72 ret 732: 74 jeql 1f /* if divisor=1, return dividend */ 75 cmpl r0,r2 /* unsigned comparison between */ 76 jgequ 2f /* dividend and divisor */ 77 clrl r0 /* dividend < divisor, return 0 */ 78 clrl *4(ap) /* save result */ 79 ret 802: 81 movl $1,r0 /* dividend >= divisor, return 1 */ 821: 83 movl r0,*4(ap) /* save result */ 84 ret 85